Two recent studies looked at dementia risk — one linking resting heart rate with cognitive decline, the other tying cataract surgery to lower dementia incidence. MedPage Today spoke with Claire Sexton, DPhil, director of scientific programs and outreach at the Alzheimer’s Association, about what these findings might mean.
Following is a transcript of her remarks:
We know that targeting modifiable risk factors is extremely important in changing the trajectory of the types of statistics associated with Alzheimer’s and dementia. And some risk factors are relatively well established.
So we know what’s good for the heart is good for the head, but other risk factors are more emerging. These studies were identifying factors like cataract extraction and then also resting heart rate – elevated resting heart rate – as novel risk factors for Alzheimer’s and dementia.
A couple of things that were particularly encouraging about this was that we know that resting heart rate is simple, it’s easy to obtain, it’s routinely measured already, and also there are ways to reduce an elevated resting heart rate. So the next key question for that study is really whether reducing resting heart rate through interventions can impact upon cognition and also reduce risk for dementia.
With the study looking at cataract extraction and vision loss, which showed that people who had cataract extraction had reduced risk, you know, this is important because then it is showing that not only these factors, like vision loss, are associated with increased risk, but then by intervening we can then reduce risk. So that type of study really is advancing the field.
And there’s also research going on into understanding why that could be. So it could be that vision leads to withdrawal from activities and social isolation; that is a known risk factor for dementia. But there also could be some more direct links. We know that sensory loss leads to reduced neuronal input, and that could be important. So there’s a lot of research going on, but with I think 35 million people worldwide who are known to have cataracts, targeting it has potential to scale.
So I think for clinicians then, really this emphasizes the importance of not just being mindful of cognitive changes, behavioral changes, but also keeping a close eye on sensory impairment and cardio risk factors. Because all of these are really important in influencing somebody’s risk profile, so assessing and also treating where appropriate.
There are currently six million people age 65 years and older who are living with Alzheimer’s in the United States, and on the current path, that number is expected to more than double to 12.7 million by 2050. So targeting these types of modifiable risk factors can play a key role in delaying the onset of dementia and changing the trajectory of those statistics.